#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
#define rep(i, a, b) for (int i = (a); i <= (b); i++)
#define per(i, a, b) for (int i = (a); i >= (b); i--)
#define endl '\n'
const int N = 1005;
const int M = 1e5 + 5;

int n, m;
int f[N];
void init(int n) { rep(i, 1, n) f[i] = i; }
int find(int x) { return f[x] == x ? x : f[x] = find(f[x]); }
bool merge(int x, int y) {
  int fx = find(x), fy = find(y);
  if (fx == fy) return false;
  f[fy] = fx;
  return true;
}
struct Edge {
  int x, y, t;
  bool operator<(Edge o) const { return t < o.t; }
} e[M];
int main() {
  ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  cin >> n >> m;
  init(n);
  rep(i, 1, m) cin >> e[i].x >> e[i].y >> e[i].t;
  sort(e + 1, e + m + 1);
  int ans = -1;
  int cnt = n - 1;
  rep(i, 1, m) {
    if (merge(e[i].x, e[i].y)) cnt--;
    if (!cnt) {
      ans = e[i].t;
      break;
    }
  }
  cout << ans;
  return 0;
}